1. Field of the Invention
This invention relates to arrangements for supporting optical fiber cables and more particularly it concerns novel optical fiber racking and distribution frame systems having housing assemblies for supporting optical fiber cables in a manner which protects the cables from harmful bending and at the same time allows a large number of such cables to be readily accessed for connecting, splicing and for storage.
2. Description of the Prior Art
It is known to construct optical fiber distribution frames by providing cable connectors, cable splice supports and cable storage spools inside stacked box-like housings and to feed optical fiber cables between an overhead cable racking system and the housings. It is also known to mount the cable connectors, cable splice supports and cable storage spools in trays which are pivotally mounted in a housing to swing from an enclosed portion within the housing to an access position substantially outside the housing. A single swingable tray may be provided with cable connectors, cable splice supports and cable storage spools or it may be provided with only one or two of these different types of cable handling means. Examples of such arrangements are described in U.S. Pat. Nos. 4,765,710, 4,792,203 and 4,824,196.
There are certain problems associated with the handling of optical fiber cables. Firstly, it is important that they be properly supported to extend along predetermined paths and that they be protected from sharp bends; otherwise their signal transmission capabilities will be severely reduced. Secondly, optical fiber cables are generally used in high density environments, such as telephone exchanges and, accordingly, large numbers of cables must be handled in as small a space as possible. Thirdly, because facilities which use fiber optic cables are often modified and expanded, it is necessary that the installation in which they are mounted itself be adaptable to modification.